Mario and Sonic Adventure
by Doctor-Mechano
Summary: Bowser and Dr. Eggman have teamed up to take over both their worlds! It's up to Mario, Sonic, Luigi, and Tails to put a stop to their interdimensional plot and save the day!


Mario & Sonic Adventure

by Dr. Mechano

* * *

><p><strong>Prologue:<strong> Terrible Team-up!

It was a typical night at Bowser's Castle. The sturdy keep was bustling with activity as the officers of the Koopa Troop filed into a large conference hall, decked out with imposing stone columns and even more imposing statues of their commander. Surrounding the stage was a moat of lava, rife with Podoboos who watched from the sidelines, occasionally leaping up to get a better view. It was a full house, packed mostly with Goombas and Koopa Troopas, though the occasional Boo, Thwomp, and Chain Chomp could be spotted throughout the crowd.

Amidst the adoring cheers of his underlings, King Bowser Koopa stood at a little podium, completely dwarfing it with his towering frame. Though a Koopa himself, he greatly differed from the diminutive turtles in his army, bearing a spike-covered shell, sharp claws, and a mane of bright red hair. He gave a hearty laugh and waved to his troops, before gesturing dismissively to calm them down. As the crowd's chatter quieted, the Koopa King spoke up.

"Bwa ha ha! Have I got an _awesome_ scheme for you guys!" the royal reptile chortled, taking a step forward and dramatically throwing his hands in the air, "This time, we're gonna kidnap Peach, crush Mario, and conquer this measly Mushroom Kingdom once and for all!"

A lone Paragoomba fluttered in through a window and began awkwardly sifting through the crowd toward the stage. "Ack! ...Excuse me... Sorry!"

Bowser continued, "We're gonna do this thanks to my _totally__great_ strategy, which is... is... Er..." Bowser's eyes darted down and to his left, at the Paragoomba hovering mere inches away, a look of urgency on its face. Bowser's own face took on an annoyed scowl, _"__What __is __it? _Can't you see I'm in the middle of my big bad rousing speech?"

"Sir, I hate to interrupt-" the flustered Paragoomba said, before being cut off.

"Then _don't,__"_ Bowser said in a clearly irritated tone.

"It's kind of an emergency..." the Paragoomba mumbled.

"Whatever it is can _wait,_ can't it?" Bowser snapped, causing the small creature to flinch reflexively.

"Er... N-no sir, it really _can't,__"_ the minion mumbled.

Bowser just raised an eyebrow and frowned, silently gesturing for him to get to the point, with a look on his face expressing that this had _better_ be important.

"Sir," the Paragoomba whispered timidly, "Our intelligence has reported a heavyset mustachioed fellow in red clothes, storming the castle at this very moment!"

A mustached man? In red? _"__Mario...__"_ Bowser growled, his chipper mood utterly ruined. What was he doing here _now?_ Bowser hadn't even done anything yet! No matter- If the portly plumber was here, Bowser wouldn't back down.

Bowser turned back toward his troops, who were all looking on curiously. "Alright, you guys! Looks like that loser Mario decided to show up and crash our party!"

Surprised at the news, the troops began to murmur amongst themselves. They clearly weren't expecting to have to deal with Mario this soon.

The king raised a fist to the air, and shouted "Let's show him what we think of uninvited guests! _Crush __him!__"_

Shouting a battle cry, Bowser's troops poured out of the room to confront their enemy. Bowser, meanwhile, snapped his fingers as the stage rose to the next floor like an elevator. From the roof, he'd be able to keep an eye on the action.

Peering over the edge of the roof's fortified walls, Bowser caught sight of his army rushing out to meet the intruder below.

"What the...?" Bowser squinted at the man in the distance, as he leaped over lava pits and dodged the castle's automated traps, floating by them gracefully with the aid of a jetpack-like contraption strapped to his back. When Bowser's underlings _did_ arrive, the intruder made short work of them, blasting them with a beam that froze them in their tracks.

"Heehee!" the man snickered, "How _nice_ of you all to come out to greet me! Regardless, I'm not here to see _you,_so why don't you take some time off while I have a word with your boss?"

From this scene, Bowser quickly noticed a couple of things: First, this obviously _wasn't_ Mario, which he figured anyone could deduce from a moment's glance; Getting the Paragoombas glasses would be a top priority after he took care of this. The man wore a bright red jacket adorned with golden buckles, draped over a black pair of pants seamlessly connected to his metallic-heeled shoes. Though his face _did_ bear a large mustache, his his head lacked a familiar hat (and hair), and beady pince-nez spectacles obscured his eyes.

The second thing Bowser noticed was that this strange man was absolutely _wrecking_ his army. He seemed unfazed by the castle's defenses, and giddily rushed forward, grinning with manic glee as he fired away with his blaster.

"Who's this chump think he is?" Bowser shouted, furious at the newcomer for just waltzing into his castle and making fools of his troops. "I won't stand for this!"

Bowser took two steps back, then charged for the edge of the roof, leaping down to the ground below. Leaping slightly in place, Bowser raised his fists in a fighting stance and called out his uninvited visitor, "Alright, wise guy! I don't know what your game is, but it ends here! C'mon, let's go!"

"Ooh hoo hoo!" The man in red casually strode toward him, away from a pileup of frozen minions a few feet behind, undaunted by Bowser's growing anger, "Bowser, old boy, is that any way to welcome a _guest_ into your humble- dare I say, _very_ humble- home?"

Bowser tilted his head curiously, but maintained his fighter's stance. This guy was familiar with him- annoyingly so- but Bowser had no idea who _he_ was. "Just who are _you_ supposed to be? And whaddya want with my castle anyway? I don't even know you!"

The gentleman smiled, "I am Dr. Ivo Robotnik, scientist extraordinaire. You can just call me Dr. Eggman.I'm from another world, and I came all this way to meet you! As for _why_ I'm here... Heh heh heh..."

Bowser scowled impatiently as Eggman chuckled to himself, still quite on edge.

"Aw, come now- _Relax.__" _Eggman smirked,_ "_I'm not here to _fight_ you, that's for sure. I've done a bit of reading up on you, Bowser- And you seem like _just_ the sort of guy I want on my side! Ergo, I'm offering an alliance!"

"An _alliance? _You've got a funny way of showing it, coming in and attacking my men!" Bowser gestured to his stasis-frozen troops a short distance away.

"That's hardly fair," Eggman shrugged nonchalantly, "_Your_ troops attacked _me_ first, before I could even meet with you. Chalk _my_ actions up to self-defense."

...Bowser _did_ do that, he admitted to himself.

"Don't worry about them. I simply used a harmless freezing ray on your troops to keep them out of my hair! It's one of my..." he raised a hand to his mouth to stifle a yawn, "..._non-lethal_ weapons. Give them an hour or so, and they'll be _just __fine.__"_

Bowser unconsciously eased up a bit, lowering his guard, but he was still pretty apprehensive of this "Eggman" character, regardless.

"Be that as it may," Bowser responded, "What makes you think I have any interest in working with you?"

Eggman wrapped his arm around Bowser's shoulders, careful to avoid his spiny shell, "Bowser, my friend... You and I actually have a lot more in common than you'd think. Much like you, I'm a man of vision! I plan to take over my world and establish a glorious new age under my rule! I'm sure you can relate."

Bowser glanced at him, annoyed, but remained silent.

"Of _course_ you can," Eggman smirked, before frowning slightly, "But there's always been one _little_ hindrance to my otherwise-perfect schemes- An irritating little rodent named Sonic, whose heroic meddling always ruins everything! But _you_ know what that's like, don't you, Bowser? It _must _be grating to be bested by the same plumber time and time again. Which brings me to my proposal..."

Bowser hesitated momentarily, before responding, "I'm listening."

Eggman threw his arms up merrily, breaking into maniacal laughter, "Aaaah ha ha ha ha! Oh, you'll _love_ this. What if I told you that, with a little work, we could acquire enough power to instantaneously conquer both our worlds and crush our enemies forever?"

"I'd call you _crazy,__"_ Bowser responded, before adding, "...but go on."

"Your world has seven powerful items called the Star Pieces, which are said to grant wishes..." Eggman began, "Am I right so far?"

Bowser nodded, "Well, sure..."

Eggman continued, "Excellent. And _my_ world has a similar set of seven items- the Chaos Emeralds, mystical gems that hold _untold_ amounts of energy. However, even _with_ these powerful gems in my possession, I've been bested by Sonic. Powerful though they are, their ability to stay charged up is _incredibly limited, _and they can only put out so much energy at a time. To my understanding, your Star Pieces can only grant so many wishes at a time as well, so I imagine harnessing their power would hardly be foolproof either. But that brings me to my main point..."

Bowser looked on with great interest as Eggman kept talking, "By combining the Star Pieces and the Chaos Emeralds, I've calculated that we would be _completely_ unstoppable. The two sets would continuously power each other up in an infinite cycle, preventing either from running out of juice! That means..."

"Limitless energy... and limitless _wishes,__"_ Bowser finished Eggman's sentence for him.

Eggman's smile grew even wider, "Exactly. With both the Star Pieces and Chaos Emeralds in our possession, reality itself would become our plaything! And not even our mutual foes could stand against us. Still, it's a daunting task, and I want to make sure you're _interested..._So how about it, Bowser? Do we have a deal?"

The scientist extended his hand toward Bowser expectantly. Bowser hesitated slightly before answering.

"Hmph, deal," Bowser extended his own arm, meeting Eggman in a handshake.

"Oh ho ho! _Wonderful!_ I just know that this is the start of a fantastic partnership!" Eggman turned dramatically, "Let's get going then! There's _so __much_ to do, and I simply can't _wait_ to get started!"

* * *

><p><strong>Chapter<strong>**1:** Welcome to Warp Zone!

Station Square was a typical coastal city in the United Federation, prized for its beautiful beaches, active commercial district, and- most notably- its railway transit system. The bustling city was a popular spot due its status as one of the country's most active business hubs, and its railways seamlessly connected it to nearly every major town in the region. But the city's biggest claim to fame was being rescued by the world's fastest superhero, Sonic the Hedgehog.

The blue hedgehog was renowned for his speed, and had defended the city from the sinister scientist Dr. Eggman in the past, most memorably fighting against an ancient water creature he unleashed upon the town. Since then, the city held an annual celebration in honor of Sonic's heroism.

"It was certainly nice of the mayor to throw us a party, huh, Sonic?"

Sonic's best friend and sidekick, the boy genius Miles Prower, casually walked alongside the hedgehog hero as they headed down the street toward the train station. Miles was a young fox with an unusual physical anomaly: He had been born with two tails, which could be rotated like makeshift helicopter blades, allowing him to fly. Hence, for better or worse, "Tails" became his enduring nickname.

"To be honest, I wasn't even gonna _go_ at first," Sonic said, shrugging, "But when I heard he was throwing a feast in our honor, how could I say no? Heh, I've never been one to turn down free food!"

Tails suppressed a giggle. In truth, Sonic quite enjoyed being the center of attention, but he wasn't about to let on to that.

"Anyway," Sonic said as he continued walking, "Where to now, Tails?"

"Hm... Well, wanna head back to my place? I've been making some modifications to the Cyclone, and I could a little help testing it out."

Sonic grinned and gave a thumbs-up, which over time had become his trademark pose. "Sure thing, bud! Let's go!"

As soon as he said this, the blare of police sirens sounded in the distance, growing gradually louder.

Sonic's ears perked up, and he turned slightly toward the direction of the sound. In a moment, a police car passed. It was soon followed by a second, and then a third. A dozen more soon followed, speeding down Station Square's busy streets. A few GUN Beetles- small hovering military robots- were following after them.

"Whoa, what's going on?" Tails asked.

Sonic's eyes narrowed, and his cocky smirk was replaced by a look of stern determination. He turned back to Tails to respond.

"Trouble."

Without wasting another second, Sonic sped off after the police, with Tails following a short distance behind.

* * *

><p><em>"<em>_Ooh __hoo __hoo! _Fantastic job, boys! Now to get our hands on that Chaos Emerald and make tracks!_"_

Dr. Eggman stood in the lobby of the Station Square Bank, clasping his hands gleefully. In his company was an entourage of Badniks- robots of his own design- as well as a squadron of Bowser's shelled warriors, the Koopa Troopas; Both teams of minions were holding up the bank's patrons as Eggman gloated.

One particular Koopa stood nearby, donning a blue robe and wielding a magic wand.

"You heard the man," the robed Koopa said to the bank's manager as he waved his wand at him, "Let's have that Emerald!"

_"__Right __away, __sir...__"_ the manager droned as he shuffled awkwardly to the vault and began entering its combination.

"Heehee! I've _got_ to hand it to you, Kamek- Your magic makes larceny _loads_ easier," Eggman said, playfully waving his hand in front of an entranced security guard's face, who simply stood there, not responding.

The manager opened the vault, revealing the red Chaos Emerald, which he quickly handed over to Eggman.

"Ahh, _beautiful,__"_ Eggman said, grinning at his own reflection in the gem's shiny surface, "...and the Emerald's not bad-looking either! Now, let's go _before-__"_

Eggman was cut off in mid-sentence by the bank's front doors flying open, as Sonic and Tails dashed into the room and skidded to a halt.

"Yo Eggman! I _figured_ it was you," Sonic said.

The bank's customers looked relieved at Sonic's arrival. He'd always beaten Eggman before, so they knew they were in safe hands.

"Ah, _Sonic,__"_ Eggman said cheerfully, "How _annoyingly __predictable_ of you."

"What are you up to this time, Eggman?" Tails asked.

Eggman laughed, "Heehee! If I _told_ you, I'd have to _kill_ you! ...Actually, I'll just kill you _anyway._ Kamek! Be a pal and whip up a distraction for these two, would you?"

"Certainly, Doctor," Kamek surveyed the room, his eyes happening upon a small beetle-like robot of Eggman's- a Motobug. "Ah, you'll do nicely!"

The Motobug clanged its short metallic pincers together, answering with a _"__Chiiirp! __Chiiirp!__"_

Kamek readied his magic wand, aiming it at the robot. _"__Ho'okalakupua!__"_

A blast of magical energy fired at the robot, which glowed an eerie white for a second, and then began to change shape. The robot's size dramatically increased, growing taller and wider by the second, until it was nearly twice the size of Eggman! Gone were the small pincers, replaced by large, jagged metallic scythes. The robot's cute little chirp had been upgraded to a deafening roar, sounding off as the transformation was complete.

"What in the world _is __that?__"_ Sonic asked.

"Success!" Kamek shouted, "I'll call him the magically enhanced Badnik: Mega Motobug!"

Eggman smirked, "Well, Sonic, it's been _such_ fun, as always- But I simply _must_ be on my way now. I know you'll be a good hero and protect all these innocent bystanders from my little pet, rather than follow me, so... _Ciao!__"_

"Eggman! Wait!" Sonic shouted.

Laughing all the way, Eggman skipped out the door, followed by Kamek, the Koopa Troopas, and the rest of his Badniks. He'd gotten away with one of the Chaos Emeralds, and that _wasn't_ good.

Still, right now Sonic had bigger problems to worry about. In front of him stood a giant Motobug, waving its sharp scythes around wildly. Sonic had to stop it before someone got hurt.

"Okay, Tails," Sonic called back to his friend, "You ready to take this thing?"

Tails nodded, "Let's do it, Sonic!"

The Mega Motobug roared angrily, and charged forward, slashing away with its blades, one of which headed right for Sonic.

"Gah!" Sonic ducked under the whirling metal blade in the nick of time, and it instead sliced a large wooden desk in half. "Hoooo boy, so yeah, we've gotta be careful... And I've gotta end this quick."

Sonic dashed away from the door, all the way to the far side of the bank, "C'mon and get me, big guy! What's the matter, too fast for ya?"

Furious, the robot turned around and charged for Sonic, who at the last minute leaped out of the way as it rammed into the wall.

"Quick, get outta here!" Sonic shouted at the innocent bystanders, who wasted no time rushing out of the now-clear doorway. With them out of the way, he'd at least have one less thing to worry about in this fight.

With the Motobug still reeling from its impact with the wall, Sonic took the opportunity to spin right into it for a direct attack... only to bounce right off, without leaving so much as a dent in its outer shell.

"That weirdo wizard must've boosted its defenses too," Sonic said, "Hey, Tails! We need to find a weak spot on this thing!"

"Right!" Tails shouted as he flew overhead, looking over the machine for any flaws he could recognize. "Ah, Sonic! I found something!"

The Motobug slashed at Sonic again, who jumped over one scythe, before ducking under the next.

"Great, Tails!" Sonic shouted, dodging another attack, "What is it?"

"The metallic casing at the very top of its shell looks corroded, and is probably weaker than the rest. With enough force, it would most likely shatter to pieces!"

Sonic grinned, side-stepping another scythe attack, "Awesome, Tails! Gimme a boost, would ya?"

Tails nodded, and flew just over Sonic, who leaped up and grabbed his hands.

Sonic weighed a bit more than Tails, so he couldn't carry him for too long. Fluttering to the best of his ability, the young fox positioned Sonic directly over the robot's shell, "Ready, Sonic?"

"Aw, _yeah!__" _

Sonic let go of Tails's hands and allowed gravity to do the rest as he curled into a ball and spun downward into the robot's weak spot, crashing into it with his spinning spines. The impact, as Tails predicted, caused the robot's shell to crack right open and split apart. A burst sent scrap metal flying everywhere.

When the dust cleared, a little bunny popped out of the metallic debris and scampered off.

"Whew..." Sonic panted, "That was a bit tougher than I expected..."

"I wonder..." Tails said, rubbing his chin, "Who that wizard was, and where Eggman was headed."

Sonic scratched his head, "I dunno, Tails..."

A restroom door opened, and one of the Koopa Troopas from earlier walked out, before noticing the scene before him. The other Troopas had already left, and he'd apparently missed the whole heist. Too flustered to notice Sonic and Tails, the Koopa quickly ran out the door to catch up to the others.

"...but I bet I know how to find out. Let's see where this guy takes us!"

Tails nodded, and the two followed, keeping enough distance to go unnoticed by the turtle. He took a really indirect route through the back alleys of Station Square, and on the way, the heroes could see disabled police cars and GUN Beetles- likely a result of them running into Eggman on his way from the bank.

Finally, the Koopa Troopa entered an abandoned building. It was tucked away in an inactive part of town, though the bustling Twinkle Park could be seen on the horizon. Sonic and Tails cautiously entered the building after him, and saw the turtle hop down a large green pipe.

"This is getting fishy," Sonic said, "But I'll bet if we follow him, we'll find Eggman!"

"You're probably right," Tails said, "Let's go, but be careful."

Sonic nodded, the two hopped in. Sonic wasn't expecting what came next at _all._

The two soon found themselves flying at breakneck speed through a colorful tunnel of lights and sounds, no longer surrounded by the green metallic tubing of the pipe they'd entered. After a few moments, they shot out of a pipe identical to the one they'd entered, and landed abruptly on the ground before it.

"Ugh, my head..." Sonic said, reeling from the trip, "Where... are we?"

Sonic and Tails observed the locale, taking note of a few immediately-apparent oddities: Brick blocks were floating in the air, abnormally large mushrooms were growing all over the place, and the hills _literally_ had eyes. Wherever they were, it wasn't Station Square.

The hedgehog and fox didn't have long to take in their surroundings, however. Out of nowhere, a gloved fist met Sonic's face and knocked the unsuspecting hedgehog aside.

"What the...? _Ow!"_

_"Yahoo!"a voice shouted._

It was soon followed by another, somewhat quieter voice, "_H-hey bro! You okay?"_

The first voice responded with a brief "Mm-hm!"

"Sonic!" Tails shouted in surprise.

"U-ugh..." Sonic looked up, still collecting his thoughts after having taken a pretty brutal hit, and saw two men dressed in red and green, each assuming a fighting stance.

"W-Who...?"

**TO BE CONTINUED...**


End file.
